The Buick Motor Company was started in 1903 by David Dunbar Buick in Detroit. The company was taken over by James Whiting later that year, and moved to Flint, MI. In 1904 William Crapo (Billy) Durant, a successful manufacturer of horse-drawn vehicles, joined Buick, and became General Manager by 1908. (wikipedia) He formed General Motors either with only Buick or as a holding company then put Buick into it.  Although Billy Durant was a high school drop out, he was an entrepreneur of the first order.

Billy Durant

The gmnext.com history wiki notes:

Under the guidance and persistence of Billy Durant, a company called General Motors was established on September 16. Its initial holdings included only Durant’s Buick Motor Company and went un-noticed in the news media, with the major business news story that day being the announcement by the White Star Line shipping company that it would begin construction of the world’s largest ocean liner, to be called the Titanic.

Late that year he also bought Oldsmobile. The next year he added Cadillac, Elmore, Oakland, and several other makes. But General Motors marks their birth as 1908. So on Tuesday, 2008 they will officially be 100 years old.

GM is marking the celebration in an appropriate 2008-era way by conducting activities on the internet.
Please check in at GM Next http://www.gmnext.com to participate in the planned celebration, discussion, interaction, and broadcast.

Commemorate the day with a series of forward-looking activities right here on GMnext.com. Join in the first day of GM’s next 100 years. Here’s what we have planned:

* Global Broadcast 8:30 a.m. EDT
* Virtual Chats beginning at 10:30 a.m. EDT
* Future of Transportation Roundtable 1:30 p.m. EDT

Happy 100th Birthday General Motors

The Auto Writer also has coverage of the event. (wave)